$ git clone -n https://src.fedoraproject.org/rpms/kf6-kbookmarks.git /var/lib/mock/f42-build-side-1-3585588-46906/root/chroot_tmpdir/scmroot/kf6-kbookmarks
Cloning into '/var/lib/mock/f42-build-side-1-3585588-46906/root/chroot_tmpdir/scmroot/kf6-kbookmarks'...
$ git fetch origin 729e8a042c29e4e930e53fd93a986d896dab1d01:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kf6-kbookmarks
 * [new ref]         729e8a042c29e4e930e53fd93a986d896dab1d01 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 729e8a0 6.16.0